Oct 02, 2026 Rheumatoid Arthritis and Lung Disease: Why Early Detection Depends on Access to Testing
Rheumatoid arthritis (RA) is best known for painful, swollen joints. But RA is a systemic autoimmune disease, and its effects can extend well beyond the musculoskeletal system, including to the lungs.
Rheumatoid arthritis lung disease can take several forms, including airway disease, pleural disease, pulmonary nodules, and interstitial lung disease (ILD). Among these complications, rheumatoid arthritis-associated interstitial lung disease (RA-ILD) deserves particular attention because it can cause substantial morbidity and mortality, while its earliest signs may be subtle or nonspecific.
That creates an important challenge for rheumatologists, pulmonologists, and other clinicians caring for people with RA: recognizing which patients may have pulmonary involvement is only part of the equation.
Early detection also depends on access to the appropriate testing.
The 2023 American College of Rheumatology/American College of Chest Physicians (ACR/CHEST) guideline recommends pulmonary function tests (PFTs) and high-resolution computed tomography (HRCT) of the chest for screening patients with systemic autoimmune rheumatic diseases who are at increased risk for ILD. Importantly, the guideline defines PFTs as including spirometry, lung volumes, and diffusing capacity for carbon monoxide (DLCO).
When these tests are difficult to access, however, there can be a meaningful distance between recognizing the need for evaluation and actually obtaining it.
That access gap deserves more attention.
How Rheumatoid Arthritis Affects the Lungs
The relationship between rheumatoid arthritis and the lungs is complex.
RA can affect multiple pulmonary structures, and respiratory complications may result from the underlying autoimmune disease, associated inflammation, treatment-related effects, infection, environmental exposures, or other comorbidities.
Pulmonary manifestations associated with RA include pleural disease, airway disease, rheumatoid nodules, pulmonary vascular involvement, and several forms of interstitial lung disease.
RA-ILD is among the most serious of these complications.
Interstitial lung disease is an umbrella term for disorders involving inflammation and/or fibrosis of the lung parenchyma. In RA-ILD, these changes can affect the lung’s structure and its ability to transfer oxygen efficiently.
The clinical course varies substantially from patient to patient. Some individuals have radiographic abnormalities with few respiratory symptoms, while others develop progressive breathlessness, declining lung function, and fibrotic disease. RA-ILD has also been associated with poorer physical function, reduced quality of life, and increased mortality.
This variability makes pulmonary involvement difficult to identify based on symptoms alone.
It also explains why assessing the rheumatoid arthritis lungs requires more than simply asking whether the patient feels short of breath or relying on one pulmonary measurement.
Different components of pulmonary function testing provide different physiologic information. Spirometry evaluates airflow and measures parameters such as forced vital capacity (FVC). Lung volume testing can help identify restrictive physiology. DLCO evaluates the lungs’ ability to transfer gas across the alveolar-capillary interface.
For patients at increased risk for ILD, the ACR/CHEST guideline specifically considers all three components part of PFT evaluation.
Who Is Most at Risk for RA-ILD?
Not every person with rheumatoid arthritis develops RA-ILD, and individual risk cannot be determined from one characteristic alone.
However, research has identified several factors associated with a higher likelihood of RA-associated interstitial lung disease.
These include older age, male sex, cigarette smoking, and certain RA-related characteristics. Seropositivity and higher levels of rheumatoid factor or anti-citrullinated protein/peptide antibodies have also been associated with ILD risk in multiple studies.
A recent systematic review and meta-analysis likewise identified older age, male sex, smoking history, and several other clinical characteristics as factors associated with development of RA-ILD.
Risk factors are useful because they can help clinicians decide when the threshold for further pulmonary evaluation should be lower.
They are not, however, a substitute for testing.
Nor does pulmonary disease necessarily follow a predictable timeline after the onset of joint symptoms. Clinicians therefore need to consider both a patient’s underlying risk and any new respiratory findings over time.
The ACR/CHEST guideline takes a risk-based approach rather than recommending identical screening for every patient with RA. For people with systemic autoimmune rheumatic diseases considered at increased risk of ILD, it conditionally recommends screening with PFTs and HRCT rather than relying on clinical history and examination alone
That distinction is important: risk assessment should help determine who needs closer evaluation, while access determines whether that evaluation can actually happen efficiently.
Warning Signs That Are Easy to Miss
When rheumatoid arthritis affects the lungs, the first signs may not be dramatic.
Common manifestations of RA-ILD include progressive shortness of breath with exertion and a persistent dry cough. Fine inspiratory crackles may also be identified during physical examination. Yet some patients with pulmonary abnormalities may have minimal or even no significant respiratory symptoms at the time abnormalities are discovered.
This creates a diagnostic challenge because neither cough nor breathlessness is specific to ILD.
A patient may attribute reduced exercise tolerance to age, deconditioning, joint pain, weight, or simply being less active. Clinicians may also need to consider cardiovascular disease, anemia, infection, airway disease, medication-related effects, and other causes of respiratory symptoms.
RA itself can make recognition more difficult.
A person whose joint disease already limits walking may not perform enough physical activity to recognize a gradual decline in exercise tolerance. Older adults may interpret increasing breathlessness as a normal consequence of aging rather than a reason to raise a pulmonary concern.
Clinical history and auscultation remain important, but they have limitations as screening tools.
The ACR/CHEST guideline notes that the diagnostic accuracy of symptoms and physical examination alone is insufficient for screening patients at increased risk. Even mild pulmonary symptoms or subtle reductions in physical activity warrant attention. ([ACR/CHEST Guideline](https://acrjournals.onlinelibrary.wiley.com/doi/10.1002/acr.25347))
That is where objective testing becomes important.
How Lung Involvement Is Detected
Evaluation of suspected RA-associated lung involvement may involve several complementary tools.
HRCT plays a central role in identifying and characterizing interstitial abnormalities. Pulmonary function testing answers a different question. Rather than showing lung anatomy, it quantifies how the respiratory system is functioning.
For evaluation of patients at increased risk for ILD, comprehensive PFT may include:
Spirometry, which measures airflow and ventilatory parameters such as FEV1 and FVC
Lung volumes, including total lung capacity, which can help characterize restrictive physiology
DLCO, which evaluates gas transfer across the alveolar-capillary membrane
The inclusion of all three measurements is not simply a matter of offering more data.
According to the ACR/CHEST screening and monitoring guideline, PFTs for systemic autoimmune rheumatic disease-associated ILD should include spirometry, lung volumes, and DLCO. The same guideline conditionally recommends HRCT plus PFTs over PFTs alone for screening people at increased risk, underscoring the complementary roles of physiologic testing and imaging.
DLCO is particularly relevant when interstitial involvement is a concern.
Studies of patients with RA have demonstrated patterns of pulmonary impairment that include restriction as well as isolated reductions in DLCO. Patients with RA-ILD have also demonstrated lower DLCO and total lung capacity compared with patients with RA without ILD.
That does not mean an abnormal DLCO diagnoses RA-ILD.
DLCO can be affected by multiple pulmonary and nonpulmonary conditions, and patients with early or mild ILD may still have normal PFT results. HRCT is more sensitive for detecting interstitial abnormalities, which is why pulmonary physiology needs to be considered alongside imaging and the clinical picture. ([PMC](https://pmc.ncbi.nlm.nih.gov/articles/PMC5045096/))
But it does mean that spirometry by itself does not provide the complete physiologic assessment contemplated in current ILD screening guidance.
For clinicians evaluating patients at risk of RA-ILD, the relevant question is therefore not simply:
Can we perform spirometry?
It is:
Can we obtain the pulmonary measurements needed to evaluate physiology comprehensively when ILD is a concern?
Why Early Detection Is So Hard
The challenges surrounding early RA-ILD detection are usually discussed in clinical terms.
Symptoms can be nonspecific. Risk differs between patients. HRCT findings vary. PFT results need clinical interpretation.
But there is another challenge: access.
Consider a patient attending a routine rheumatology visit.
The clinician identifies new exertional dyspnea or recognizes that the patient has several RA-ILD risk factors. A pulmonary evaluation is warranted.
If comprehensive PFT is not available within the practice, the next step may involve an external referral.
That can mean another order, another scheduling process, another location, another appointment, and another transition of information back to the referring clinician.
Every additional handoff creates another opportunity for delay.
The problem is not that referral is inappropriate. Pulmonology referral and multidisciplinary care are essential in many cases.
The problem arises when the infrastructure required to obtain basic objective pulmonary data becomes a barrier in itself.
This is where the distinction between **spirometry and complete PFT** becomes especially important.
Spirometry is compact and widely available in outpatient medicine. Historically, complete PFT, particularly lung volume measurement, has often depended on larger equipment such as a body plethysmography cabin and dedicated laboratory space.
Yet current ACR/CHEST guidance defines PFT for ILD screening as spirometry, lung volumes, and DLCO.
That creates a practical question for practices caring for patients at increased risk for RA-ILD:
What happens when the guideline-relevant measurements are available only somewhere else?
A screening recommendation is most useful when clinicians can act on it.
Clinical awareness can identify who may need evaluation. Guidelines can define the appropriate tools. But access ultimately affects how easily those tools can enter the patient’s care pathway.
Closing the Access Gap
Improving access does not mean testing every patient with RA indiscriminately.
It means making appropriate testing easier to obtain when a clinician determines it is warranted.
Technology is changing what pulmonary function testing requires from a practice.
PulmOne’s MiniBox+ provides spirometry, lung volume measurements, and single-breath DLCO in a compact, cabinless system designed for office and hospital use. Its lung volume measurements use a cabinless Partial Volume Method rather than requiring the patient to enter a traditional body plethysmography chamber.
That distinction can expand where comprehensive PFT can physically fit into the care pathway.
For pulmonology practices, a compact PFT system can provide flexibility in how and where testing is delivered.
For rheumatology or multispecialty settings considering greater access to pulmonary assessment, it raises a different possibility: some of the physiologic testing that would traditionally require referral to a dedicated PFT laboratory may be brought closer to the point of care.
Consider the traditional pathway:
Clinical concern → PFT referral → scheduling → separate visit → testing → results → follow-up
When appropriate testing is available on site, some of that distance can potentially be reduced:
Clinical concern → objective pulmonary testing → interpretation and next clinical step
This does not eliminate the role of pulmonologists.
It does not replace HRCT.
And it does not mean pulmonary function testing alone can establish a diagnosis of RA-ILD.
What it can change is access to physiologic information.
That distinction matters because current clinical guidance calls for more than spirometry when PFT is used in this setting.
The MiniBox+ performs the three major components identified in the ACR/CHEST definition of PFT for ILD screening: spirometry, lung volumes, and DLCO.
For practices seeking to close the distance between identifying pulmonary risk and obtaining objective pulmonary data, that creates a new option.
A Team-Based Approach to Care
Rheumatoid arthritis-associated lung disease sits naturally at the intersection of rheumatology and pulmonology.
Rheumatologists are often well positioned to recognize changes in symptoms or risk because they follow patients longitudinally for RA.
Pulmonologists bring specialized expertise in pulmonary physiology, ILD evaluation, imaging correlation, differential diagnosis, treatment, and long-term respiratory monitoring.
Radiologists and other specialists may also play important roles, particularly when HRCT abnormalities need to be interpreted in the broader context of autoimmune disease.
Current ACR/CHEST guidance reflects the importance of this collaboration. The guideline was developed to support both the identification of ILD by rheumatologists and the co-management of systemic autoimmune rheumatic disease-associated ILD by rheumatology and pulmonary specialists.
The goal, therefore, is not to shift responsibility for RA-ILD from one specialty to another.
It is to reduce the barriers between suspicion, testing, interpretation, referral, and ongoing management.
Better access to comprehensive pulmonary function testing can support that model by helping objective physiology become available earlier in the clinical pathway.
For the patient, fewer logistical steps may mean fewer opportunities for an important evaluation to be delayed.
For the clinician, easier access can mean obtaining more complete physiologic information when deciding what should happen next.
Access Is Part of Early Detection
Rheumatoid arthritis is a systemic disease, and evaluating its potential impact on the lungs requires looking beyond the joints.
RA-associated interstitial lung disease can be difficult to recognize because symptoms may be subtle, risk varies across patients, and no single clinical finding establishes the diagnosis.
Current ACR/CHEST guidance recommends PFT and HRCT for screening patients with systemic autoimmune rheumatic diseases who are at increased risk of ILD. It defines PFT as including spirometry, lung volumes, and DLCO.
That definition matters.
It reinforces that when ILD is the clinical concern, spirometry alone is not equivalent to comprehensive pulmonary function testing.
But even the right testing strategy has limited value if patients cannot easily access it.
When complete PFT depends on a separate referral, a separate facility, and another appointment, logistical distance becomes part of the detection pathway.
Compact, cabinless PFT technology offers an opportunity to shorten that distance.
With spirometry, lung volume measurement, and DLCO available in one compact system, PulmOne MiniBox+ is designed to make comprehensive pulmonary function testing possible across a broader range of clinical settings.
For clinicians caring for patients with rheumatoid arthritis, that reframes an important question in early lung-disease detection.
It is not only:
Who should be evaluated for lung involvement?
It is also:
How easily can the right patient get the right testing at the right time?
References
- American College of Rheumatology/American College of Chest Physicians. 2023 ACR/CHEST Guideline for the Screening and Monitoring of Interstitial Lung Disease in People with Systemic Autoimmune Rheumatic Diseases. Arthritis Care & Research.
- American College of Rheumatology. Interstitial Lung Disease Clinical Practice Guidelines.
- England BR, et al. Rheumatoid arthritis-associated interstitial lung disease: Current update on prevalence, risk factors, and pharmacologic treatment.
- Cassone G, et al. Interstitial Lung Disease in Rheumatoid Arthritis: A Practical Review.
[View the peer-reviewed article on PubMed Central](https://pmc.ncbi.nlm.nih.gov/articles/PMC9136053/)
- Shaw M, et al. Rheumatoid arthritis-associated lung disease.
- RA-ILD clinical literature. Pulmonary abnormalities in RA may include restrictive physiology and isolated reductions in DLCO, while HRCT remains important for detection of early or mild ILD.
- Hackner K, et al. Screening for rheumatoid arthritis-associated interstitial lung disease: a Delphi-based consensus statement.
- PulmOne. MiniBox+ Technical Specifications.Product specifications for spirometry, cabinless lung volume measurement, and DLCO.